Single Sign-On with SAML: A Practical Guide

Discover the benefits of Single Sign-On (SSO) and Security Assertion Markup Language (SAML) can’t be ignored anymore. Learn how SSO streamlines user experience and enhances security, how SAML enables secure user authentication across multiple systems, uncover the differences between SAML and SSO, SAML SSO workings, and learn about the implementation steps in this guide.

What Is Single Sign-On?

Single sign-on (SSO) is a user authentication process that enables users to access multiple applications and services with a single set of login credentials. The purpose of SSO is to simplify the user experience and improve security by reducing the number of times that  users must enter their credentials. This is often the case in most B2B settings today, where dozens of SaaS apps need to be accessed on a daily basis.

For example, consider a user who needs to access multiple applications, such as their email apps, task management tools, automation software, productivity solutions, company portal, and more. With SSO, users can enter their login credentials once, and then have access to all of these applications without having to enter their credentials again. This saves time and effort as they only need to remember one set of login credentials, while also reducing the risk of password fatigue. Without SSOusers often choose weak passwords or reuse passwords across multiple applications.

Additionally, SSO can improve security by reducing the number of times that user must enter their passwords, something that reduces the risk of password theft and also simplifies user account administration. Changes to the user’s information or permissions can be made in one central location and automatically apply to all of the applications that the user can access.

What Is SAML?

Security Assertion Markup Language (SAML) is a standard for exchanging authentication and authorization data between various parties, such as an identity provider (IdP) and a service provider (SP). The purpose of SAML is to provide a secure and standard way for organizations to manage user authentication and authorization across multiple systems and applications.

For example, consider a user who needs to access an application provided by a service provider. The user attempts to access the application and is redirected to the IdP for authentication. The IdP verifies the user’s credentials and generates a SAML assertion, which contains information about the user’s identity and attributes. The IdP then sends the SAML assertion to the SP, which uses it to grant the user access to the application.

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SAML vs. SSO: What Are the Differences? 

SAML (Security Assertion Markup Language) and SSO (Single Sign-On) are related but distinct concepts.

SAML is a standard for exchanging authentication and authorization information between parties, such as an identity provider (IdP) and a service provider (SP). It is an XML-based format for encoding security assertions that can be transmitted over the internet. SAML provides a way for the IdP to securely assert the user’s identity to the SP, and to pass along authorization information that the SP can use to make access control decisions.

SSO, on the other hand, is a user authentication process that allows a user to access multiple applications with a single set of credentials. The goal of SSO is to simplify the user experience and reduce the need for users to remember multiple sets of credentials for different applications.

While SAML is often used to implement SSO, it is not the only way to do so. Other standards, such as OAuth and OpenID Connect, can also be used to implement SSO. SAML, however, is well-established and widely used, and provides a high degree of security and interoperability between different systems and organizations.

How SAML SSO Works

SAML SSO works by exchanging SAML assertions between an identity provider (IdP) and a service provider (SP).

• User accesses the service provider’s application: The user attempts to access a protected resource on the service provider’s website.
• Service provider redirects the user to the identity provider: The service provider sends a SAML authentication request to the identity provider.
• User authenticates with the identity provider: The user provides their credentials to the identity provider, which then verifies the user’s identity.
• Identity provider sends a SAML assertion to the service provider: If the user is authenticated, the identity provider creates a SAML assertion that contains the user’s identity and other relevant information.
• Service provider grants access to the user: The service provider uses the information contained in the SAML assertion to grant the user access to the requested resource.

This process allows the user to authenticate once with the identity provider and then access multiple service provider applications without having to re-enter their credentials. SAML also enables secure sharing of user information between trusted business partners.

Implementing SSO with SAML 

There are two types of SSO implementations using SAML: 

• SP-initiated SSO: The user attempts to access the application provided by the SP. The SP redirects the user to the IdP for authentication. The IdP verifies the user’s credentials and generates a SAML assertion, which is sent back to the SP. The SP uses the information in the SAML assertion to grant the user access to the application.
• IdP-initiated SSO: The user first logs in to the IdP and is then able to access the applications provided by the SPs without having to enter their credentials again. The IdP generates a SAML assertion and sends it to the SP, which uses the information in the assertion to grant the user access to the application.

For example, consider a user who needs to access a company portal and their email. The company has set up an IdP and the portal and email are provided by two separate SPs. In an SP-initiated SSO scenario, the user attempts to access the portal and is redirected to the IdP for authentication. The IdP verifies the user’s credentials and generates a SAML assertion, which is sent back to the portal. The user is now able to access the portal without having to enter their credentials again. In an IdP-initiated SSO scenario, the user first logs in to the IdP, and then has access to both the portal and their email without having to enter their credentials again.

Implementing SSO with SAML involves the following steps:

1. Setting up the identity provider (IdP): The IdP is responsible for verifying the user’s credentials and generating a SAML assertion that contains information about the user’s identity and attributes. The IdP must be set up and configured to support SAML.
2. Setting up the service provider (SP): The SP is the application or resource that the user is trying to access. The SP must be configured to accept SAML assertions from the IdP and to use the information contained in the assertion to grant the user access to the application.
3. Configuring the SAML connection: The IdP and SP must be configured to communicate with each other using SAML. This involves exchanging metadata between the IdP and SP, which contains information about how to communicate using SAML.
4. Testing the SAML connection: Once the SAML connection is configured, the IdP and SP must be tested to ensure that they are communicating correctly and that the user can access the application using SSO.

SSO with Frontegg 

Frontegg’s self-served SSO solution allows smooth and seamless implementation (and modification) of SSO flows with just a few lines of code. There are no frustrating support tickets, nor is there any unwanted in-app friction. These SSO flows can be integrated with leading protocols like OIDC and SAML, as explained in-depth in this article. Yes, there’s also smooth social login integration on offer for added customer satisfaction.

Frontegg also handles the front end with a fully customizable login box that saves valuable in-house development time and boosts productivity. This box can be embedded into your SaaS app in no time, another key component in a truly end-to-end user management solution.